I have taken several apart as I investigate orig clutches and pressure plates. With the clutch press which I had available, taking apart is not hard. You will probably find it may have been rebuit before, or the plate may be in poor shape.
Beware there were Heavy duty housing, levers and eyebolts. Thicker metal and larger eye bolts. Also there were high grade pressure plate. Most likely they will be warped and possibly bad heat spots. If warped significantly not worth having it machined. The plate may also be thin from a prior rebuilt.
You can test springs like valve springs and early service manual has the spring spec. Make sure you document how it comes apart.
Look for cracks in levers, worn pins, eyelets, pressure plate, etc...

I had 2 plates redone for Hemi specific 101/2" housing. Have reenforced plates for the rollers. It was a fun exercise, but I would not put it in a drag car.